In symptomatic people COVID-19 is most infectious just before, and for the first few days after symptoms begin. It is very important people with symptoms self-isolate and get a test, which will allow contact tracing.
Evidence, although still limited, has strengthened and shows that people with COVID-19 who are mildly ill and are recovering have a low but real possibility of infectiousness between 7 and 9 days after illness onset.
We have considered how best to target interventions to reduce risk to the general population and consider that at this point in the epidemic, with widespread and rapid testing available and considering the relaxation of other measures, it is now the correct balance of risk to extend the self-isolation period from 7 to 10 days for those in the community who have symptoms or a positive test result.
This will help provide additional protection to others in the community. This is particularly important to protect those who have been shielding and in advance of the autumn and winter when we may see increased community transmission.
Chief Medical Officer for England, Professor Chris Whitty
Chief Medical Officer for Northern Ireland, Dr Michael McBride
Chief Medical Officer for Scotland, Dr Gregor Smith
Chief Medical Officer for Wales, Dr Frank Atherton